Research On The Calculation Method Of The Life Span Of The Solar Rice Grain Tissue

Solar granulation is a kind of morphological characteristics of solar photosphere caused by convective motion.It is a solar structure in the solar photosphere,shaped as a cellular pattern,surrounded by dark lanes.Calculating the mean life-time of solar granulation can help astronomers to better understand the mechanism of the convective motion and the relationship to solar magnetic field.Due to the evolution of the solar granules is more complex.And the morphological characteristics and the strength of solar granules are constantly changing with the time.The traditional tracking methods have calculation deviation in the morphological tracking of solar granules,so we can't track the solar granules with morphological characteristics.Therefore,we calculate the life-time of solar granules with two different ways.We calculate the life-time of solar granules based on the centroid tracking method and the power spectrum analysis based on periodic analysis method.Based on the centroid tracking method mainly calculates the life-time of individual solar granule,and the power spectrum analysis based on periodic analysis method to calculate the life-time of all solar granules.We selected the high-resolution image sequences taken from the Hinode Solar Optical Telescope to illustrate based on the centroid tracking method of calculating the mean life-time of solar granules and the power spectrum analysis based on periodic analysis method to calculate the mean life-time of solar granule.In this paper,the main work is as follows:The main idea of based on the centroid tracking method of calculating the mean life-time of solar granules includes these steps:(1)firstly,based on phase congruency to identify solar granules;(2)secondly,according to the result of identify to calculate the centroid position of solar granules;(3)at last,selecting some solar granules from the image sequences random,then we label them and tracking them forward and backward,until we tracked the birth and the death of solar granules,calculating the mean life-time of them.The power spectrum analysis based on periodic analysis method to calculate the mean life-time of solar granules include these steps:(1)firstly,we use the ?-? filter to remove the 5-minute oscillations.Only removing the 5-minute oscillations can we more accurately calculate the mean life-time of solar granules;(2)secondly,we use gradient transformation to remove the direct current component(DC component)and reduce spectral energy leakage with the Hamming Window;(3)at last,using the function of Periodogram calculates the mean life-time of solar granules.In order to verify the accuracy of the method,we set three data to calculate the mean life-time of solar granules.According to the two kinds of different methods to calculate the mean life-time of solar granules,we compared the two methods with its experimental results and the calculating method.The results based on the traditional method of calculating the mean life-time of solar granules as follows,there are 50 solar granules,the mean life-time of solar granules is 7.6 min.The final results of the power spectrum analysis based on periodic analysis method to calculate the mean life-time of solar granules are 9.24 min,9.04 min and 10.67 min respectively.As a result of the existence time of solar granules is very short and the evolution is more complex,identifying the fragmentation and merging of solar granules will get us into trouble.We calculate the life-time of solar granules with two different methods.Based on the centroid tracking method mainly calculates the life-time of individual solar granule,and the power spectrum analysis based on periodic analysis method to calculate the life-time of all solar granules.The two kinds of calculating methods cross-validate each other,which proves that our calculation method is accurate and effective.